<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<title>Document</title>
	<style>
		div{
			width: 100px;
			height: 100px;
		}
		.one{
			background-color: red;
		}
		.fixed{
			background-color: blue;
			/*固定定位
				postion:fixed
				特点:1.脱离文档流 原先位置不保留 飘在文档流上方
				2.相对于浏览器视口区域进行定位
			*/
			position: fixed;
			bottom: 50px;
			right: 50px;
		}
		.two{
			background-color: yellow;
		}
	</style>
</head>
<body>
	<div class="one"></div>
	<div class="fixed"></div>
	<div class="two"></div>
</body>
</html>